1. Field of the Invention
The present invention relates to means for securing heat sinks, and particularly to a heat sink clip for attaching a heat sink to an electronic device such as a computer electronic package.
2. Related Art
Developments in integrated circuits have resulted in greater circuit density and complexity, thus increasing heat generated by operation of such integrated circuits within an electronic package. Therefore, bigger and heavier heat sinks are becoming increasingly necessary to efficiently remove the heat. Thermal interface material (TIM) is usually applied onto the electronic package where it contacts the heat sink. TIMs are pressure sensitive. When a large heat sink is attached to an electronic package by, say clips, the retaining force applied by the clips must be uniform. Otherwise, the TIM will not function efficiently.
Nowadays, strong resilient clips are often used to attach heavy heat sinks onto electronic packages. The force required to keep a heat sink in place is correspondingly large. Operators or end users must exert great manual force when attaching a retainer clip to a socket or to a motherboard. Extra tools are often required for installation or removal of the clip. There is considerable risk that during use of such tools, nearby components such as the motherboard itself will be accidentally damaged.
Therefore, an improved heat sink clip which overcomes the above-mentioned problems is desired.
Accordingly, an object of the present invention is to provide a heat sink clip for readily attaching a heat sink to an electronic device such as a central processing unit (CPU), and for readily detaching the heat sink therefrom.
Another object of the present invention is to provide a heat sink clip which does not need extra tools in assembly or disassembly.
A further object of the present invention is to provide a heat sink clip which resists movement of the clip and an associated heat sink when they are subjected to vibration or shock.
To achieve the above-mentioned objects, a heat sink clip assembly in accordance with the present invention attaches a heat sink to a CPU that is mounted to a mother board. A heat sink clip in accordance with a preferred embodiment of the present invention comprises a first bar, a second bar slidably attached to the first bar, and a handle pivotably attached to the first bar. Two legs respectively depend from opposite ends of the first and second bars. Two tabs extend inwardly from the legs, each tab defining a slot. The handle has a shaft and a pressing cam. A back plate is placed under the mother board. Two posts are successively extended through bores of the back plate, apertures of the mother board, and holes of the heat sink. The posts are then engaged in the slots of the clip. When the shaft is rotated downwardly, the pressing cam presses against the heat sink, and the first and second bars resiliently deform upwardly. The clip thus secures the heat sink to the CPU.